OBJECTIVE: To study the meridian tropism(MT) for three Chinese medicines: Tinglizi(Semen Lepidii Apetali, TLZ), Yiyiren(Semen Coicis, YYR), Cheqianzi(Semen Plantaginis, CQZ) in vivo experiments.METHODS: The extracts of TLZ,YYR, CQZ were orally administered to rats at a dose 234, 700 and 350 mg/kg, respectively. The urinary excretion rate, loss in weight of rats and the electrolyte levels in the plasma were measured, in order to assess the mechanisms of the three traditional Chinese diuretic medicines.RESULTS: TLZ, YYR and CQZ exhibited obvious diuretic effect and reduced the weight of saline-loaded animals. All the three diuretic medicines differentially reduced various serum, urinary, lung, stomach, kidney and hormonal markers, thus indicating the different mechanisms of action and a close resemblance with their different meridian as per the MT theory.CONCLUSION: Our findings suggest that the three Traditional Chinese Medicine(TCM) medicines-TLZ,YYR and CQZ-possess different Shamisen meridian.This can support the regimen of treating the same disease with different therapies in TCM theory.